Heater control valve
 

Where is the heater control valve at on a 1998 Expedition (4.6). thanks

There's a heater control valve?

I do not think most Ford's have one. I think coolant flows thru the heater core all the time.

Maybe better than having coolant just sit in the heater core all during warmer months

I don't believe there is a control valve per se.:-X15 The engine coolant is always circulating throughout the system and the infamous blend door controls the heat or cooling you get in the cabin of the truck. I believe there is a vacuum operated valve on the F250's and Excursions, but not sure. You may have to repair the blend door and there are many posts regarding this.

Thanks for the replies, I have found outt hat there is no HCV and I have already visualy inspected the blend door and it works good. I believe i am going to think i have a clogged heater core and/or line. thanks

You might try reverse flushing the heater core to clear it. Have you ever used any kind of radiator stop leak stuff in your truck?

no I have not use any kind of stuff like that, I will do the flushing and see what comes of it. With the rear unit, is there anything to do or should i flush the whole deal for the heat in rear is alittle warmer than front but nothing you would want to be in a long time in the winter in the new england area. thanks

I would try flushing the whole system with plain water. I am not a fan of the corrosive radiator flush products as they can cause even bigger problems. It could be something as simple as a blockage at the hose connection at the engine or in the hose itself.

Thanks:-X22